1. Field of the Invention
The present invention relates to a television broadcast receiving device constructed to wirelessly transmit a video/audio signal to a display section based on a television broadcast signal received by a tuner section.
2. Description of the Background Art
Display screens of recent television broadcast receivers are thinned out, and products such as wall-hanging televisions go on sale. In such flat-screen televisions, tuner sections that receive and decode broadcast are separated from display sections that display the broadcast on display screens. Interfaces such as HDMI transmit video/audio signals from the tuner sections to the display sections through cables. In order to omit the cable connection between the tuner sections and the display sections, products that adopt the wireless transmission of video/audio signals from the tuner sections to the display sections start to go on sale.
“Electronic Engineering Times, June 2, pp. 10-11” proposes Wireless HD, WHDI (Wireless High Definition Interface) and UWB as wireless transmission systems. Video signals of a base band are transmitted from tuner sections to display sections, and the transmission speed of HDTV signals is 1.5 Gbps. For this reason, various ideas are devised so as to stably transmit video signals of high bit rate. National Publication of Translation No. 2007-507147 (pp. 6-10) describes one concrete example that structures a system being capable of displaying video data of high bit rate without discontinuous screen using a compressing method for separating image data into a rough portion and a fine portion and an MIMO wireless technique even under a noise-rich environment.
In above television broadcast receiving device in which tuner sections and display sections are separated, the following problem of the conventional arts arises. Even when the tuner sections and the display sections are installed in a good visibility state therebetween, data are not always stably transmitted in a wireless manner. For example, when obstacles are provided to a wireless transmission path, radio waves are blocked by the obstacles, and thus the receiving strength on a receiving side is deteriorated or the wireless communication is cut off. Further, in some cases, humans, animals and things move on the wireless transmission path, and thus the communication state changes. Further, the communication state is changed by exogenous noises such as jamming from things other than an installed wireless device (a tuner section and a display section). In this situation, when wireless communication is conducted by the tuner section and the display section that are installed in respective rooms, interference with wireless LAN might disable stable transmission of video and audio.
In such a manner, the communication state always fluctuates due to the influence of humans, animals and things moving on the wireless transmission path and the arrival of exogenous noises. When the communication state is deteriorated, a transmission rate of data is deteriorated as compared to a case where the wireless transmission is normally performed, thereby causing data missing. In the transmission of AV data composed of video data and audio data, the deterioration of the transmission rate due to the change in the communication state causes deterioration of image and sound qualities. When a transmittable rate is deteriorated and the wireless transmission is cut off, video data cannot be transmitted. This problem cannot be solved until a communication route is restructured or the influences of exogenous noises are eliminated. When the communication state is recovered, video data can be transmitted. That is to say, when the communication state is deteriorated, the video data cannot be transmitted during this state, and thus a portion of broadcast that cannot be viewed by a user is generated. As a result, the user cannot sufficiently understand the contents of the broadcast.